I don’t know about you, but Thursday afternoons are when my weekend plans start to take shape. And tomorrow, after my laptop is shut down and I exchange my button-down for a t-shirt, I’ll be heading in to D.C. for the evening by way of the Metro, alongside countless others. The same scenario will undoubtedly play out in every other major city with a subway-esque train system.

The Washington Metro opened its doors in March of 1976. Today’s photo shows people waiting in line at the Rhode Island Avenue station for a free Metro ride on opening day, March 27. In the near future, Northern Virginia residents will experience another “opening day line” as Metro opens the first phase of the Silver Line route.